Impairment in Baroreflex Sensitivity in Recent-Onset Type 2 Diabetes Without Progression Over 5 Years.

Impaired baroreflex sensitivity (BRS) predicts cardiovascular mortality and is prevalent in long-term diabetes. We determined spontaneous BRS in recent-onset diabetes patients and its temporal sequence over 5 years by recording beat-to-beat blood pressure and R-R intervals over 10 minutes. Four time domain and four frequency domain BRS indices were computed in participants from the German Diabetes Study baseline cohort with recent-onset type 1/type 2 diabetes (n=206/381) and age-matched glucose-tolerant controls (Control 1/Control 2: n=65/83) and subsets of consecutive type 1/type 2 diabetes participants who reached the 5-year follow-up (n=84/137). Insulin sensitivity (M-value) was determined using a hyperinsulinemic-euglycemic clamp. After appropriate adjustment, three frequency domain BRS indices were reduced in type 2 diabetes compared to Control 2 and were positively associated with M-value and inversely associated with fasting glucose and HbA1c (P<0.05), whereas BRS was preserved in type 1 diabetes. After 5 years, a decrease in one and four BRS indices was observed in type 1 and type 2 diabetes patients, respectively (P<0.05), which was explained by the physiologic age-dependent decline. Unlike well-controlled recent-onset type 1 diabetes patients, those with type 2 diabetes show early baroreflex dysfunction, likely due to insulin resistance and hyperglycemia, albeit without progression over 5 years.